The focus for this proposal is on prevention research in Botswana to reduce incidence of HIV/AIDS. This is central to the current research activities of the faculty mentors, who collaborate extensively with each other and with key partners at the Botswana site. Our partner for training is the Botswana Harvard AIDS Institute Partnership (BHP), a limited liability nonprofit corporation (LLC) with the Ministry of Health (MOH) in Botswana. The BHP is the largest HIV/AIDS research organization in Botswana, and one of the largest in Africa. The long- term goals and objectives of this training program are to train research leaders who can take responsibility for the BHP within the next 5-10 years, and to staff the MOH with local AIDS experts. Botswana currently has the second-highest prevalence of HIV in the world for adults (25%), but has also had the highest rate of antiretroviral drug treatment (ART) for patients with AIDS (about 90%, according to WHO). The government of Botswana, the training faculty at Harvard, and the key collaborators at BHP have now decided to focus their efforts on prevention research. A new research grant based on a combination of prevention interventions includes participation by 10 of the 14 Harvard training faculty. AIDS-related courses, seminars, and workshops are available for trainees. We have requested funds for 2 predoctoral and 3 postdoctoral positions each year. We estimate that we will train about 18 trainees over 5 years, allowing for multiple years for each PhD candidate and some postdoctoral fellows, and assuming several short-term trainees could fill a single annual training slot. Stipends will be based on current degrees and research experience; thus an MD on an MS or PhD program would be eligible for a postdoctoral-level stipend. All trainees would have at least a BSc degree. We estimate that about half will be physicians with clinical experience. Some will be postdoctoral fellows who have PhD's in a related area but no experience in AIDS research. Each trainee will have a principal advisor and a faculty advisory committee. Selection of trainees is based on previous academic performance, references, experience, and assurance that the candidates will return to participate in AIDS research in Botswana. The quality of the program will be monitored by a Training Advisory Committee composed of experts from the US and from developing countries. The success of the training program will be judged by the relative increase in senior research positions at BHP and MOH that are individuals who were trained by this program after the second and fourth years. Success will also be judged by the implementation of successful prevention research programs that involve trainees, numbers of trainee publications in high-impact journals, and number of staff positions filled by former trainees at the BHP and the Ministry of Health.